Spreaders, such as broadcast spreaders are used across an array of applications, including farms, golf courses and residential properties, to apply particulate, such as grass seed, fertilizers, snow and ice salt/sand and the like. As such, these spreaders may need to cover a large area. To apply particulate material to these large areas, broadcast spreaders generally include a hopper, impeller, shaft and two wheels supported by an axle. The hopper holds a large volume of material which is funneled to an outlet such that the material may fall onto the impeller. A gear assembly is mounted on the axle between the wheels whereby rotation of the axle along a horizontal axis is translated to rotation of the shaft along a vertical axis. The impeller is mounted on the shaft such that rotation of the shaft causes rotation of the impeller. As a result, the impeller may then cast the particulate material across the coverage area. Locomotion of the spreader may be manual, such through use of a push bar, or mechanical, such as through mounting the spreader to a tractor, all-terrain vehicle (ATV) or other similar vehicle.
One drawback to these systems, however, is that the particulate matter continues to fall through the outlet onto the impeller even when the spreader is not moving. As a result, the particulate material builds up on the impeller, and may even overflow the impeller and fall directly on the grass/surface. The material build-up will then be immediately dispersed once the spreader is again moving. However, the volume of material immediately dispersed will be significantly larger than during the remainder of the spreading operation. This large amount of material may be damaging to the grass/surface and also results in a waste of material, thereby increasing cost of operation. This drawback also leads to a further waste of time and/or material. For instance, a user may load the hopper with a volume of material estimated to complete the intended task. However, if the task is completed with material still in the hopper, a user may simply continue the spreading operation until the hopper is emptied rather than attempting to pour the unused material from the hopper into a container, thereby wasting material and incurring additional time to empty the hopper. Conversely, if too little material was added, the user will be forced to reload the hopper, taking time, and then continue operation until the hopper is empty, as described above.
To alleviate the above drawback, spreader systems have been developed whereby a shut off plate is positioned proximate the discharge opening of the hopper. While such systems may mitigate waste of material by closing the hopper discharge when material is not to be dispersed, these systems are tedious as an operator must continually manually adjust the shut off plate to open and close the discharge openings of the hopper, particularly when using a tow-behind spreader. Alternatively, mechanical systems have been designed which have a powered actuator which selectively opens or closes the shut off plate. However, such systems are costly and have a large number of moving parts. Actuation of the shut off plate via a battery may also require manual input of the operator.
Thus, there remains a need for a spreader that can broadcast particulate while the spreader is moving but automatically prevent unwanted build-up of material on the impeller when the spreader is stationary. The present invention satisfies this as well as other needs.